Why should I analyse PFAS?
Why should I analyse PFAS?
PFAS is associated with a number of health effects, for example, effects on the thyroid gland, liver and fat metabolism. In addition, the hormonal and the immune systems can be affected by long-term exposure, but further research is needed. The same applies to cancer at “low” exposures. However, PFAS is not stored in adipose tissue in the same way as many other organic pollutants. Another difference is that PFAS occurs in the form of both mono- and polymers, even though it is the monomers that are of primary importance in the food chain. Longer PFAS molecules (>C6-C8, depending on structure) are usually considered bioaccumulative, and therefore of importance to determine in food/biota. The same can be the case for certain precursors e.g. PFOSA that can form PFOS at degradation. Eurofins also provides a complete range for all types of samples with leading reporting limits.
EFSA's TWI value for PFAS4 of 4.4 ng/kg body weight/week from 2020 has raised the awareness of food, not at least fish and baby food (see “legislation”). Moreover, research shows that crops and fruits can take up PFAS to some extent as well. Limit values within the EU for PFAS4 (individual and sum) will be in force from 2023. There is also a recommendation for a screening within the union 2022-25.
The overall knowledge on the levels present in different foodstuffs is still limited. Most of the old data is of less use because of high reporting limits (LOQ) compared to what is needed to correlate with TWI. There is a risk of high levels in foodstuffs due to local “hot spot” contamination, but also a lower “background” levels in much of the produce due to diffuse contamination everywhere in the environment. Given the widespread use, not at least of new “novel” PFAS, levels in some foods and thus the risk of exposure may increase for a long time.
There is a number of possible causes of contamination in food. One major source can be irrigation with contaminated water e.g. downstream from hotspots. This can cause elevated levels in milk or meat from cows (or other animals) drinking from the same water. The Korsør case in DK is one example of this. Fish and shellfish from these contaminated waters are another example together with contaminated silage, grass or other feed from the same sites. Another potential source that has been highlighted in e.g. the US recently, is crops grown on sludge-fertilized fields which is used as food or feed.
In this context it should also be highlighted that food can be contaminated from packaging material, but also other material in contact with the food. The use of PFAS, the compounds allowed and migration is restricted for FCM plastics in Regulation (EU) 10/2011. For paper/board there is no common EU regulation but since 2020 there is a ban for all PFAS in DK and SE is expected to follow. There are also national legislations and recommendations e.g. in NL and DE. A recent report from the Swedish Chemical Agency (KEMI 5/21) demonstrated the presence of PFAS in a number of paper and board packages/wrappings.
More recently reports have highlighted the presence of so called PFAS pesticides. This has concerned the number of such pesticides, their rapidly increased use in the EU and the fact that residues are found in fruits and vegetables. PAN (Pesticide action network Europe) has stated that 37 active substances in use in the EU are defined as PFAS. This has been followed up with investigation of the occurrence of PFAS pesticides in fruit and vegetables across the EU. It was shown that in 2021, pesticides classified as PFAS could be found in 20% of EU-grown fruit/berries and 12% of vegetables. Typically the PFAS moiety (acc to OECD definition) of the pesticide molecules is a trifluoromethyl (-CF3) group. Addition of such a group may improve stability, but in the case of C-CF3 the moiety can cause formation of trifluoroacetic acid (TFA), an ultrashort PFAS, at degradation.
